No the VPN will work from the LAN port, I found this out by accident. Thing is it doesn't seem to work on the same subnet and it's not possible to set the router up so that wireless lan traffic is on a separate subnet.

I've got a bluetooth lan and since they are separate devices I managed to set the WRV54G on subnet 10.... and the bluetooth lan on 192.... . The only thing that stopped a VPN connection was the same problem I'm having on the WAN port, a lack for NAT-T support.